超细碳酸钙填充型粉末NR的研究

以NR胶乳为原料，超细碳酸钙为填料，高分子树脂为包覆剂兼超细碳酸钙表面改性剂，用凝聚共沉法制备填充型粉末NR。研究了产物粒径及其硫化胶力学性能的影响因素。结果表明，当包覆剂的用量为20质量份时，超细碳酸钙表面改性剂用量为4－5质量份，超细碳酸钙填充量为100－175质量份，可获得粒径≤0.9mm的超细碳酸钙填充型粉末NR达94．5％以上；超细碳酸钙填充量为25－200质量份的范围内，其硫化胶具有优良的力学性能，并显著优于块状NR／超细碳酸钙通过机械混烧所得到的硫化胶，扫描电镜分析显示超细碳酸钙以原生粒子均匀分数于NR基体中，二者形成的界面结合牢固。

A Study of the Ultra-fine Calcium Carbonate-filled Powdered NR

Ultra-fine calcium carbonate-filled NR powder was prepared with coacervation-coprecipitationmethod,using polymeric resin as both encapsulant for product particle and surface modifier for ultrafine calcium carbonate.The effective factors of the filled NR powder particle size were studied.The results show that the recovery ratio of the product with particle diameter 0.9mm was greater than or equal to 94.5% when 20 phr of encapsulant and 100-175 phr of ultra-fine calcium carborate,which was modified by 4~5 phr of surface modifier,were loaded in the powered system.The vulcanizate gave very good mechanical properties as the content of ultra-fine calcium carbonate is between 25%-200% by mass,much better than those of vulcanizate of bale NR/ultra-fine calcium carbonate mixed stock.SEM analysis showed that the ultre-fine calcium carbonate paricle dispersed uniformly in the rubber matrix and the interface adhered tightly.